The objective of this research is to determine whether the biotinyl enzyme content of liver of Sudden Infant Death Syndrome (SIDS) is reduced relative to the biotinyl enzyme content of age-matched controls. Work from other laboratories has shown that total biotin content of SIDS livers is lower than that of controls. A method has been developed in this laboratory by which the quantity of individual biotinyl enzymes can be measured. This method has been used in preliminary studies of a limited number of samples which showed that individual biotinyl enzymes were reduced in autopsy samples from SIDS victims. This project seeks funding for the analysis of a larger number of age-matched samples. If the preliminary results are confirmed, this will be the first distinct biochemical defect observed in SIDS and would serve as a basis for further investigation of the etiology of this disease. In addition, if reduction of one or more of the biotinyl enzymes is a consistent finding in SIDS, this could serve an important function of aiding in a definitive diagnosis of the syndrome.